#include "xian.h"
#include <cmath>

Xian::Xian(double qidian, double zhongdian) :
    qidian(qidian), zhongdian(zhongdian)
{
}

Xian::~Xian()
{
}

double Xian::GetChangDu() const {
    return std::abs(0.5*zhongdian - 0.5*qidian);
}
